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A023300 Numbers n such that n remains prime through 3 iterations of function f(x) = 10x + 3. 1
2, 7, 17, 19, 23, 61, 101, 103, 409, 719, 857, 997, 1297, 1531, 1699, 2399, 3253, 3491, 4583, 4933, 5119, 5189, 5939, 6277, 6863, 7789, 8669, 9187, 9887, 10061, 10253, 10267, 11027, 11777, 12791, 12899, 13669, 17209, 17293, 17489, 17839, 19211, 19379 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n, 10*n+3, 100*n+33 and 1000*n+333 are primes. - Vincenzo Librandi, Aug 04 2010

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Prime[Range[2200]], And@@PrimeQ[NestList[10#+3&, #, 3]]&] (* Harvey P. Dale, Feb 21 2013 *)

PROG

(MAGMA) [n: n in [1..450000] | IsPrime(n) and IsPrime(10*n+3) and IsPrime(100*n+33) and IsPrime(1000*n+333)] // Vincenzo Librandi, Aug 04 2010

CROSSREFS

Sequence in context: A325510 A006883 A023269 * A317308 A045378 A101568

Adjacent sequences:  A023297 A023298 A023299 * A023301 A023302 A023303

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified October 21 12:12 EDT 2019. Contains 328299 sequences. (Running on oeis4.)